SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c511f7b013539e9ea55fad09cfa7165d847baeef9e8d32d1119e60ca5a6d5ff0' 
  AND token = '1tzABVpA/3xf8KGr3Dg9y+bOK5h2Jr8Q/9ljBIbYogc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}